Daddy daycare: Why some songbirds care for the wrong kids

Interspecific feeding—when an adult of one species feeds the young of another—is rare among songbirds, and scientists could only speculate on why it occurs, but now, Penn State researchers have new insight into this behavior.

Are humans preventing flies from eavesdropping?

Today's world is filled with background noise, whether it be from a roaring river or a well-trafficked highway. Elevated noise levels from both human-made and natural sources may interfere with animals' listening ability ...

Researchers advance noise cancelling for quantum computers

A team from Dartmouth College and MIT has designed and conducted the first lab test to successfully detect and characterize a class of complex, "non-Gaussian" noise processes that are routinely encountered in superconducting ...

Using correlated photons to enhance x-ray imaging

A team of researchers at Bar-Ilan University has found a way to use correlated photons to make sharper X-ray images. In their paper published in the journal Physical Review Letters, the group describes their process and suggest ...

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In common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise ("static") heard when listening to a weak radio transmission with significant electrical noise. Signal noise is heard as acoustic noise if the signal is converted into sound (e.g., played through a loudspeaker); it manifests as "snow" on a television or video image. High noise levels can block, distort, change or interfere with the meaning of a message in human, animal and electronic communication.

In signal processing or computing it can be considered random unwanted data without meaning; that is, data that is not being used to transmit a signal, but is simply produced as an unwanted by-product of other activities. "Signal-to-noise ratio" is sometimes used to refer to the ratio of useful to irrelevant information in an exchange.

In biology, noise can describe the variability of a measurement around the mean, for example transcriptional noise describes the variability in gene activity between cells in a population.

In many cases, the special case of thermal noise arises, which sets a fundamental lower limit to what can be measured or signaled and is related to basic physical processes described by thermodynamics, some of which are expressible by simple formulae.

In some fields, noise means unwanted information or data that is not relevant to the hypothesis or theory being investigated or tested.

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